1. Field of the Invention
This invention relates to a class of novel valence tautomeric compounds which are, in themselves, optoelectronic switching devices. More specifically, these intramolecular devices are dichalcogenide carbamate esters of dichalcogenide onium salts, compounds that are capable of undergoing valence tautomerism between degenerate cationic tautomeric forms which are optically active and enantiomeric to each other. This invention provides a class of optoelectronic compositions which can be resolved and arranged as a type of molecular switching device useful in molecular electronics.
2. Related Art
Certain 4-(N,N-dialkyldithiocarbamato)-2-alkyliminio-1,3-dithietanes have been found to exhibit valence tautomerism via a ring-opening/ring-closing reaction [R. R. Schumaker et al., J. Chem. Soc., Chem. Commun, 1991, 719], as shown in the following mechanism (scheme 1). ##STR2## The ".sup.1 H" NMR spectra of the above compound in solution provided evidence for the degenerate rearrangement between the two equivalent tautomers.
This type of intramolecular conversion would be possible between optically active tautomeric forms of molecules structurally similar to those valence tautomeric compounds described above. Such molecules, if optically resolved and assembled can be made to function as an optoelectric switching device.